Over the user-edit page, theres a checkbox with explanatory text at the bottom, like this:

[x] If you have a valid Gravatar associated with your e-mail address, use it for your user picture.
Your Gravatar will not be shown if you upload a user picture.

This checkbox goes disabled when there's a user-uploaded picture available. Because the (strange) way to delete a user-uploaded picture is checking the "Delete picture" checkbox and submitting; it's not possible to delete the user picture and enable gravatar at the same time (because gravatar checkbox will be disabled).

I say the explanatory text is enough to let people know that an uploaded picture takes precedence over a gravatar and disabling-enabling the checkbox both causes confusion and makes the workflow (even more) complicated.

So I propose we leave the checkbox always enabled and (detail) we tweak the explanatory text to: "Your Gravatar will not show if you have an uploaded user picture."

Thanks